Portable self powered line mountable device for measuring and transmitting solar radiation

ABSTRACT

A device for attaching to an electric power line conductor includes a housing with an opening for accepting the power line conductor. The housing is configured to be grounded to the power line conductor. At least one magnetic core is configured to surround the power line conductor and power a power supply electronics module. A solar sensing element is configured to be mounted horizontally on the housing.

CROSS REFERENCE TO RELATED APPLICATION

This application claims reference to U.S. Provisional Application No. 61/740,517 dated Dec. 21, 2012.

BACKGROUND

The present disclosure relates to a multiple parameter sensor-transmitter/receiver unit which may be installed on or removed from an energized electric power line, such as an overhead power line. With the advent of Smart-Grid applications for electric power systems, there is an ever increasing need for a device that measures electric, mechanical, and environmental parameters of the power line.

In order to address the increasing need for monitoring power lines, devices have been developed that attach directly to the power line. These devices generally require a power source, such as batteries or solar panels. When utilizing batteries, regular maintenance must be performed to replace the batteries, which can become costly. When solar panels are used, the device may only be powered during sunny weather conditions and during daylight hours. Therefore, there is a need for a device which is low maintenance and can be constantly powered independent of weather conditions.

One example device for measuring environmental parameters is a land based weather station. One of the significant problems of land based weather stations, even if located in close proximity at the terminal ends of the electric power line, is the measured weather data at these two locations can never be representative of the differing weather conditions the line actually experiences throughout its entire length. This is especially true for long lines traversing over various types of terrain where it may be shielded by trees and other natural obstacles such as hills and rocky formations, and the weather itself such as the amount of sunshine, fog, rain, snow and icing conditions the line is exposed to can dramatically vary from one point to another along these lines.

SUMMARY

A device for attaching to an electric power line conductor includes a housing with an opening for accepting the power line conductor. The housing is configured to be grounded to the power line conductor. At least one magnetic core is configured to surround the power line conductor and power a power supply electronics module. A solar sensing element is configured to be mounted horizontally on the housing.

A method of measuring solar radiation with a device configured to be attached to a power line conductor including signal conditioning measured values of solar radiation.

The signal conditioned measured values are sent to a remote location with a transmitter-receiver unit located within a housing. A sensor electronics module and the transmitter-receiver unit are powered from current flowing in the power line conductor. The measured values are processed to determine a current carrying capacity of the power line conductor.

These and other features of the disclosed examples can be understood from the following description and the accompanying drawings, which can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a right side view of an example sensor transmitter receiver unit (“STR unit”).

FIG. 2 illustrates a front view of the STR unit of FIG. 1.

FIG. 3 illustrates a cross-sectional view taken along line A-A of FIG. 2.

FIG. 4 illustrates a cross-sectional view taken along line A-A of FIG. 2 with an example hotstick.

FIG. 5 illustrates another cross-sectional view taken along line A-A of FIG. 2 with the example hotstick.

FIG. 5 a illustrates an enlarged view of a keyhole slot.

FIG. 6 illustrates another cross-sectional view taken along line A-A of FIG. 2 engaging a conductor.

FIG. 7 illustrates an example upper magnetic core subassembly.

FIG. 8 illustrates an expanded view of an example upper magnetic core and an example lower magnetic core surrounding the conductor and an example power supply transformer.

FIG. 9 illustrates a schematic view of the line mounted power supply, electronics and transmitter-receiver of the STR unit.

FIG. 10 illustrates an expanded view of the lower magnetic core, example lead screw assembly, and an example hotstick guide tube.

FIG. 11 illustrates the collapsed view of the lower magnetic core, the lead screw assembly, and the hotstick guide tube.

FIG. 12 illustrates a cross-sectional view taken along line B-B of FIG. 2.

FIG. 13 illustrates a cross-sectional view taken along line C-C of FIG. 1.

FIG. 14 illustrates an exploded view of example support blocks mounting the upper magnetic core subassembly and example upper and lower jaws.

FIG. 15 illustrates an exploded view of an upper magnetic core mount and the upper and lower jaws.

FIG. 16 illustrates a top view of a solar radiation sensor.

FIG. 17 illustrates an enlarged cross-sectional view of the solar radiation sensor taken along line M-M of FIG. 16.

FIG. 18 illustrates an exploded view of the solar radiation sensor of FIG. 16.

FIG. 19 illustrates a cross-sectional view of the solar radiation sensor mount taken along line M-M of FIG. 16.

FIG. 20 illustrates an exploded view of the solar radiation mount.

FIG. 21 illustrates a collapsed view of the solar radiation mount.

DETAILED DESCRIPTION

An example FIGS. 1 and 2 illustrate an example sensor transmitter receiver unit (“STR unit”) 1 installed on a power line conductor C for measuring and monitoring various parameters of the power line conductor C and its environment. The STR unit 1 is formed from a one piece upper housing 2 and a one piece lower housing 3. The lower housing 3 is accepted into a bead 4 formed on a distal end of the upper housing 2. In this example, the bead 4 which is an integral part of the upper housing 2 is formed by machining a portion of the upper housing 2 to form a groove on the inside of the bead 4. The lower housing 3 is secured to the bead 4 and the upper housing 2 by a collar 5. The collar 5 attaches to a hotstick guide tube 13 (FIG. 3) that is secured to the upper housing 2 and extends through the lower housing 3.

In one example, the upper housing 2 and the lower housing 3 are made of aluminum or other suitable electrically conductive material. The material chosen should accommodate subassembly installation without the use of external surface fasteners which could generate corona discharges due to high voltage being applied to the upper housing 2 and the lower housing 3. The upper housing 2 has the advantage of reducing the number of mating surfaces and eliminating mismatches between multiple cast parts which can generate corona discharges and audible noise due to slightly offset sharp edges of the mating surfaces of the adjacent castings.

Referring to FIGS. 3 and 4, before the STR unit 1 is clamped onto the conductor C, a lower jaw 7 is moved to its fully lowered position spaced from upper jaws 6. This allows the conductor C to pass from position “A” of FIG. 3 through a throat T on the left side of the upper housing 2 and onto the upper jaws 6 in position “B” as shown in FIG. 5.

With the lower jaw 7 of the STR unit 1 in its fully lowered position, a specially designed hotstick 10 is inserted into the bottom of the STR unit 1 and inside the hotstick guide tube 13. In this example, the hotstick 10 is made of an electrically insulated material such as fiberglass. The hotstick 10 includes a hotstick driver assembly 9 (FIG. 4) attached to the hotstick 10 with a pin 36. The hotstick 10 provides the required electrical insulation between the hands of the linemen and the energized conductor C. A flexible stirrup assembly 11 (FIG. 4) contains a flexible braided conductor 12 which bends out of the way to allow the hotstick driver assembly 9 to enter a hole in the collar 5. As mentioned earlier, the collar 5 secures the lower housing 3 to the bead 4 on the upper housing 2. The collar 5 is fastened to the hotstick guide tube 13 using the set screw 5 a which is screwed into the collar 5 and into a hole in the hotstick guide tube 13.

With the hotstick 10 and the hotstick driver assembly 9 fully engaged inside the hotstick guide tube 13, the STR unit 1 can be lifted by the lineman with the hotstick 10 onto the conductor C while maintaining the STR unit 1 securely attached to the hotstick 10.

The upper housing 2 includes two jaw inserts 8, shown in FIGS. 5 and 14, located adjacent the throat T and the upper jaws 6. The two jaw inserts 8 include inclined surfaces 8 a and the upper jaws 6 include inclined surfaces 6 a. The angle of incline of the inclined surfaces 8 a matches the angle of the incline of an inclined surface 2 a on the upper housing 2.

The angle of the inclined surfaces 6 a is steeper than the angle of the inclined surfaces 8 a and the inclined surface 2 a to aid in installing the STR unit 1 on the conductor C. As the conductor C slides across the inclined surfaces 2 a and 8 a and reaches the steeper incline of the inclined surface 6 a, the STR unit 1 will bounce slightly upward and land in a circular notch 6 b of the upper jaws 6 (See FIG. 4). This allows a conductor temperature sensor to be mounted vertically and in the middle inside the upper jaws 6 and initially extends slightly below the circular notch 6 b for the upper portion of the conductor C. The two different inclined surfaces 6 a and 8 a of the jaw inserts 8 and upper jaws 6 prevent the conductor temperature sensor S, shown in FIGS. 3 and 4, from becoming damaged since the conductor C firmly lands vertically in the circular notch 6 b of the upper jaws 6 and pushes the conductor temperature sensor S up to the inside surface of the circular notch 6 b.

In FIG. 3, the lower jaw 7 is located in a pocket P between two legs of a lower magnetic core 14. The lower jaw 7 is held in place with two spring pins 132 and 133 (FIG. 15) located in the lower jaw 7 that snap into two holes 15 in a lower jaw holder 16 (FIGS. 10 and 11) which is attached to a bottom block 19 using two screws 20 (FIG. 3). The bottom block 19 is located adjacent the base of the upper housing 2.

Two identical electrically conductive lower core covers 17 partially surround the two legs of the lower magnetic core 14. The lower core covers 17 are attached to the bottom block 19 on each side of the lower jaw holder 16 using screws 18 of FIG. 3 on the front right side and one set of the screws 18 on the back left side (not shown). The front and back lower jaw holders 16 are both held in place by the four screws 20, two in the front and two in the back. The two legs of the lower magnetic core 14 are totally encased by the two lower core covers 17 and the front and back lower jaw holders 16. Therefore, the lower magnetic core 14 is not exposed to any moisture, such as from rain, snow, and ice that could enter through the throat T of the upper housing 2 (FIG. 3).

The bottom block 19 contains a conical hole 21 in the center which provides a very low friction bearing surface for the semi-circular top of a lead screw 22 (FIG. 3). The lead screw 22 is held in the conical hole 21 with a retainer plate 23 which has a hole in the middle the size of the lead screw 22 diameter and is fastened to the bottom block 19. The lead screw 22 is threaded into the center of a threaded bushing 25. The threaded bushing 25 has a reduced diameter cylindrical lower portion which fits inside the hotstick guide tube 13 and a larger diameter cylindrical top portion of the threaded bushing 25 is supported on the upper end of the hotstick guide tube 13. Both the threaded bushing 25 and the hotstick guide tube 13 are attached to a hotstick guide support 26 using two large through bolts 27 and nuts which are placed through the holes in a bottom support 28.

Referring to FIG. 2, the upper jaws 6 include two spaced apart jaws and the lower jaw 7 includes a single jaw aligned between the two spaced apart upper jaws 6. When lower jaw 7 is clamped onto the conductor C, the conductor C is bent slightly upward as the lower jaw 7 extends upward between the upper jaws 6 creating a bending moment in the conductor C. The bending moment in the conductor C prevents the STR unit 1 from sliding down the conductor C, especially when the STR unit 1 is mounted at the point of attachment adjacent a utility pole or tower where the slope of the conductor C is at its maximum value. Preventing the upper jaws 6 and the lower jaw 7 from sliding down the conductor C at the point of attachment is necessary when the STR unit is being used to measure sag of the power line conductor.

Referring to FIGS. 5 and 5 a, the bottom support 28 includes an upside down “U” shaped cross member and is fastened at each end to the upper housing with two large threaded screws 29 on each side. The threaded bushing 25 has two small vertical holes 25 a drilled through the threaded bushing 25 on each side of the threaded hole in the middle for the lead screw 22. The vertical holes 25 a are countersunk on the top and provide drainage paths for fluid, such as rain water, that can accumulate underneath the bottom block 19 and on top of the bottom support 28 (FIG. 5 a). The water then drains through the two vertical holes 25 a in the threaded bushing 25 and drops on the inside of the hotstick guide tube 13 and out the bottom of the STR unit 1. Therefore, water will not leak into the lower housing 3.

Referring to FIG. 6, the lead screw 22 has a small diameter hotstick guide 30 which is threaded on the inside and is screwed on the bottom of the lead screw 22. A pin 31 keeps the hotstick guide 30 from turning on the lead screw 22. The hotstick guide 30 prevents the inside of a hotstick lead screw driver 33 from coming into contact with the threads on the lead screw 22 and damaging the internal bore of the lead screw driver 33. It also guides the lead screw driver 33 onto the lead screw 22. When the pin 31 engages the lead screw driver 33 the STR unit 1 is ready for installation on the conductor C.

The hotstick driver assembly 9 includes the lead screw driver 33, a hotstick driver coupling 32, a rivet 34, a hotstick sleeve 35, the pin 36, and the hotstick 10. The hotstick 10 of FIG. 4 rests on the rounded portion of the hotstick driver coupling 32 and the rounded inside bottom of the hotstick guide tube 13. This prevents the lead screw driver 33 from applying pressure to the threaded bushing 25 upon installation of the STR unit 1 on the conductor C. The lead screw driver 33 and the hotstick driver coupling 32 are each fastened to the hotstick sleeve 35 by the rivet 34 and the hotstick sleeve 35 is attached to the hotstick 10 with the pin 36. A long narrow vertical slot in the lead screw driver 33 allows the pin 31 of the lead screw 22 to be engaged with the lead screw driver 33 and is free to slide up or down in the vertical slot 37 as the lead screw is turned to tighten the lower jaw 7 on the conductor C or to loosen the lower jaw 7 from the conductor C to remove the STR unit 1.

When the hotstick driver assembly 9 is engaged with the lead screw 22 as shown in in FIG. 4, the STR unit 1 is raised to position “A” relative to the height of the conductor C. The STR unit 1 is then moved toward the conductor C so that the conductor C passes through the throat T of the upper housing 2 and into position “B” as shown in FIG. 5. Once the STR unit 1 is fully supported by the conductor C in position “B”, the hotstick driver assembly 9 is turned clockwise by the installer with the hotstick 10 and allowed to drop down from its position in FIG. 4 to a lower position as in FIG. 5. A horizontal keyhole slot 38 of the lead screw driver 33 is now engaged with the pin 31 of the lead screw 22. With the pin 31 in the horizontal keyhole slot 38, the hotstick driver assembly 9 and the hotstick 10 are secured to the STR unit 1.

In this example, an opening and closing mechanism 39 of FIG. 6 extends the lower jaw 7 upward to secure the STR unit 1 on the conductor C. Additionally, the opening and closing mechanism 39 can also retract the lower jaw 7 to remove the STR unit 1 from the conductor C. The opening and closing mechanism 39 includes the lower magnetic core 14, the lower core covers 17, the lower jaw holders 16, the lower jaw 7, spring pins 132 and 133, the bottom block 19, the retainer plate 23, two fasteners 24, the lead screw 22, the hotstick guide 30, and the pin 31.

FIG. 6 illustrates the keyhole slot 38 on the lead screw driver 33 engaged with the pin 31 on the lead screw 22. As the lead screw 22 is turned clockwise, the opening and closing mechanism 39 moves the lower magnetic core 14 toward an upper magnetic core 40. The upper magnetic core 40 has two large compression springs 41 to bias the upper magnetic core 40 downward. The compression springs 44 provide pressure to hold both the upper magnetic core 40 and the lower magnetic core 14 together to reduce the magnetic reluctance caused by air gaps 54 (FIG. 8) between the upper magnetic core 40 and the lower magnetic core 14.

The hotstick driver assembly 9 can continue to be turned clockwise even after the lower magnetic core 14 begins to mate with the upper magnetic core 40 because the compression springs 41 compress at the top of the upper magnetic core 40. The clockwise motion of the hotstick driver assembly 9 can be achieved either manually or with a battery powered drill or another rotating device, until the lower jaw 7 is tightened onto the conductor C. After the STR unit 1 is mounted on the conductor C, the hotstick 10 is turned slightly to the left, or counterclockwise, and the pin 31 will become disengaged from the horizontal portion of the keyhole slot 38. The hotstick 10 is then free to be removed when the pin 31 aligns with the vertical slot 37.

FIGS. 7 and 8 illustrate the bottom of the compression springs 41 are held in alignment in two cylindrical pockets 42 of two identical horizontal upper core blocks 43 which are each used to clamp the upper magnetic core 40 to two identical magnetic horizontal lower core blocks 44. The top of the compression springs 41 are held in place with two projections 49 extending downward on the inside of the upper housing 2. The compression springs 41 are totally enclosed by the upper housing 2 and are protected from the adverse weather which can cause corrosion. The air gaps 54 between the upper and lower magnetic cores 40 and 14 are totally enclosed by the upper housing 2 which prevents the air gaps 54 from becoming corroded due to moisture from the environment. The horizontal upper core blocks 43 and the horizontal lower core blocks 44 are clamped around the upper magnetic core 40 on each side using two through bolts 45 and two nuts 46 in the front and two through bolts 45 and two nuts 46 located in the back of the upper horizontal core blocks 43 and horizontal lower core blocks 44.

When the two large compression springs 41 push the upper core blocks 43 down, the upper magnetic core 40 is prevented from falling out of a left core shoe 50 and a right core shoe 51, by a step 52 located at the bottom of the right core shoe 51 and a step 53 located at the bottom of the left core shoe 50.

When the lower magnetic core 14 mates with the upper magnetic core 40, the lead screw 22 can be turned further clockwise to move the two upper core blocks 43 away from the steps 52 and 53 and further compress the compression springs 41. The lead screw 22 can continue to be turned clockwise and compress the compression springs 41 until the lower jaw 7 and the upper jaws 6 are tight on the conductor C.

Electrical insulating spools 47 are inserted over each of the through bolts 45 and electrical insulating washers 48 are inserted under the head of each through bolt 45 and under each nut 46. The insulating spools 47 and the insulating washers 48 on each of the through bolts 45 prevent shorted electrically conductive paths around the upper magnetic core 40 which is comprised of the four through bolts 45, four nuts 46, the two electrically conductive upper core blocks 43 and the two lower core blocks 44.

When the upper jaws 6 and the lower jaw 7 are firmly tightened on the conductor C, the compression springs 41 are compressed to their maximum distance, and thus the maximum compressive force is also applied to the lower magnetic core 14 and the upper magnetic core 40. This decreases the size of the air gaps 54 between the lower magnetic core 14 and the upper magnetic core 40 and the magnetic reluctance between the lower magnetic core 14 and the upper magnetic core 40. Depending on the size of the conductor C, varying amounts torque can be applied to the hotstick driver assembly 9 to tighten the opening and closing mechanism 39 on the conductor C.

The physical size and shape of the upper jaws 6 and the lower jaw 7 are designed such that approximately the same compressive force is applied to the upper magnetic core 40 and the lower magnetic core 14. In one example, there are five different sets of upper and lower jaws 6 and 7 that can fit different conductor sizes and types ranging from 0.162 inches in diameter and up to 1.17 inches in diameter. The opening and closing mechanism 39 allows the STR unit 1 to be installed on a wide range of conductor diameters without changing the upper jaws 6 and the lower jaws 7 while maintaining sufficient contact between the upper magnetic core 40 and the lower magnetic core 14 to complete the magnetic circuit of the power supply transformer 55 of the STR unit 1 which derives its power from the current flowing through the conductor C to power a power supply module 60 of FIG. 9. Because the STR unit 1 derives power from the conductor C, batteries or solar cells are not required to power the STR unit 1. The STR unit 1 is powered at all times when current is flowing in the conductor C, even at current levels as low as 6.8 amperes and still process data and transmit data at 1 watt power levels because of the low threshold of the power supply module 60.

Maintaining a minimum magnetic reluctance insures that a power supply transformer 55 (FIGS. 8 and 9) will provide the needed secondary voltage V₂ and secondary current I₂ to operate the power supply transformer 55, sensor electronics module 63, and transmitter/receiver 64. The power supply transformer 55 includes the upper magnetic core 40, the lower magnetic core 14, and a coil winding 56. The upper magnetic core and the lower magnetic core form a window W for accepting the conductor C.

The number of secondary turns N₂ of wire on the coil winding 56 are optimized to produce the required secondary voltage V₂ and secondary current I₂ with a minimum of current I₁ in the conductor C. The coil winding 56 is held in place by two coil bobbins 57 which are supported laterally by the two upper core blocks 43 and the two lower core blocks 44. Secondary leads 58 a and 59 a of coil windings 58 and 59, respectively, are connected to the power supply module 60 which maintains the same level of secondary voltage across leads 61 and 62 for the sensor electronics module 63 and the transmitter/receiver 64 even though the primary current may range from 34 amperes up to 1000 amperes. Lower primary currents of 6.8 amperes are achievable with the low threshold current power supply module 60. The power supply module 60 contains an energy storage device 256 (FIG. 13) which can power the transmitter/receiver 64 when the conductor C current ceases to flow. A transmitting and receiving antenna 81 for the on-board transmitter/receiver 64 is mounted on the upper housing 2 (FIG. 12).

Locating the coil winding 56, 58, and 59 on the upper magnetic core 40 allows the heat from the coil winding 56, 58, and 59 to escape through a vent 65 (FIG. 1) in the upper housing 2. When the conductor sensor S located within the STR unit 1 measures the temperature of the conductor C, it is important that the heat from the coil windings 56, 58, and 59 does not affect the temperature of the conductor C or the conductor temperature sensor S, which is in electrical communication with the sensor electronics module 63. As shown in FIG. 6, a thermally insulating barrier 66 located below the coil windings 56, 58, and 59, allows for a more accurate temperature reading of the conductor temperature by blocking heat from the coil windings 56, 58, and 59.

FIGS. 10-12 and 13 illustrate the lower magnetic core 14 with the lower core covers 17, the lead screw 22, the hotstick guide tube 13, and other related parts in both exploded and collapsed views. The hotstick guide tube 13 is anchored at the top with the through bolts 27 that extend through the bottom support 28 and the hotstick guide support 26. A round cylindrical milled slot 67 is located along opposing sides of the top of the hotstick guide tube 13 to accept the through bolts 27 that support the hotstick guide tube 13.

A central hole 70 extends through a base plate support 68 and a base plate 69 for accepting a bottom portion of the hotstick guide tube 13. The base plate support 68 and the base plate 69 are connected to each other with four identical threaded screws 71. The hotstick guide tube 13 is attached to the base plate support 68 and the base plate 69 with set screws 72 and 73. Left and right side panels 76 of FIG. 12 are attached to the base plate support 68 and the bottom support 28 for the lower core 14 with the use of two identical screws 74 extending through the bottom support 28 and the side panel 76 and at the bottom with two identical screws 75 extending through the side panel 76 and the base plate support 68.

The threaded bushing 25 rests on top of the hotstick guide tube 13 and is prevented from turning relative to the hotstick guide tube 13 using a set screw 77. The left and right side panels 76 not only provide added strength, but also provide the physical space to mount the power supply module 60, the transmitter/receiver 64, the sensor electronics 63, and support left and right lower core guides 78 and 79.

The left lower core guide 78 and a right lower core guide 79 are “U” shaped and guide the opening and closing mechanism 39 such that the lower magnetic core 14 is aligned with the upper magnetic core 40. Each of the left and right lower core guides 78 and 79 are attached to the left and right side panels 76 with four threaded screws 80. The lower housing 3 is placed over the hotstick guide tube 13 at the bottom and fitted up to the base plate 69 and held in place with the collar 5. This means that once the collar 5 is removed, the lower housing 3 can be removed thus allowing access to the power supply module 60, sensor electronics module 63, and the transmitter/receiver 64 of FIG. 9 mounted inside and on the left and right side panels 76 for easy maintenance and repair.

FIGS. 7 and 12-15 illustrate an upper magnetic core subassembly 40 a mounted to the upper housing 2. The left and right core shoes 50 and 51 support the upper magnetic core 40 such that the upper magnetic core 40 can move freely up and down inside the left and right shoes 50 and 51. The left and right core shoes 50 and 51 are attached to the upper housing 2 using four support blocks 86 and 87 of FIG. 14, right and left upper core guides 90 and 93, and four vertical through bolts 94, 95, 96, and 97.

The upper magnetic core subassembly 40 a can be inserted through the throat T and fastened to the inside of the upper housing 2. A top portion of the upper housing 2 is “C” shaped which provides a surface on the inside for mounting a current sensing device 156 for measuring the power line frequency current (60 Hz or 50 Hz) and a loop coil 157 for measuring lightning stroke current (FIGS. 13 and 16).

The right core shoe 51 has two identical threaded holes 82 and 83 on the front and back for a total of four, and left core shoe 50 has two identical threaded holes 84 and 85 on the front and back for a total of four as shown in FIGS. 7 and 14. As shown in FIG. 14, two identical support blocks 86 on the right side are placed on the front and back of the right core shoe 51 and two identical support blocks 87 are placed on the front and back of the left core shoe 50.

To align the two right side support blocks 86 with the two sets of threaded holes 82 and 83 on the right side of the right core shoe 51, threaded screws 88 and 89 are first inserted into the upper and lower holes in the right side upper core guide 90 and then through the two holes in the right support block 86 and screwed into the accommodating threaded holes 82 and 83 of the right core shoe 51. The two left side support blocks 87 are held in alignment with the left core shoe 50 by first inserting two threaded screws 91 and 92 through the other end of the right side upper core guide 90 and then through the holes in the left side support block 87 and screwed into the threaded holes 84 and 85 of the left core shoe 50. The same process is repeated on the back side by connecting support blocks 86 and 87 to the left upper core guide 93 with the backside of the right core shoe 51 and the back side of the left core shoe 50.

The purpose of the upper core guides 90 and 93 is to insure the two long vertical through bolts 94 and 95 placed through the vertical holes in the two right side support blocks 86 and two long vertical through bolts 96 and 97 placed through the vertical holes in the two left side support blocks 87 line up with the four threaded holes in four threaded inserts 98, 99, 100, and 101, which are embedded in the casting of the upper housing 2. The two right side support blocks 86 are prevented from falling down by inserting the back of a right side upper jaw holder 102 and the back of the left side upper jaw holder 103 over the vertical through bolts 94 and 95 and threading nuts 104 and 105 onto the two vertical through bolts 94 and 95 and tightening them down, respectively. The two left side support blocks 87 are held in place by inserting the vertical through bolts 96 and 97 through the front hole in the right side upper jaw holder 102 and the front hole in the left side upper jaw holder 103 and threading two nuts 106 and 107 on the vertical through bolts 96 and 97 and tightening them down, respectively.

Four threaded through standoffs 108, 109, 110, and 111 are screwed onto the four vertical through bolts 94, 95, 96, and 97, respectively. The thermal barrier 66 is placed over the four bottom holes of the standoffs 108, 109, 110, and 111 and screwed to the standoffs 110 and 111 on the front left side with two flat head screws 112 as shown in FIG. 15.

FIGS. 2 and 15 illustrate casting fillers 113 and 114 located on the back left and back right sides of the STR unit 1 and secured with round head screws 115 which are first inserted through holes in the casting fillers 113 and 114 and then through the two back holes on the right and left side of the thermal barrier 66 and into the standoffs 108 and 109, respectively.

After the upper magnetic core subassembly 40 a is mounted, the left and right lower core guides 78 and 79 including the opening and closing mechanism subassembly 39 and the left and right side panels 76 are inserted through the bottom of the upper housing 2 (See FIG. 12). Four screws 29 are inserted through the two holes on the left and the two holes on the right of the bottom support 28 and screwed into the threaded holes of the upper housing 2. It should be noted that during the insertion process, the right lower core guide 79, shown in FIG. 12, slides around the outside surface of the right core shoe 51 and underneath a tab 116 at the top as a weldment on the right upper side of the right core shoe 51.

As shown in FIG. 12, the tab 116 insures that the right lower core guide 79 fits precisely around the outside of the right core shoe 51 to provide a near perfect alignment of the lower magnetic core 14 with the upper magnetic core 40. The precise alignment between the upper magnetic core 40 and the lower magnetic core 14 reduces magnetic reluctance by decreasing the air gaps 54. This results in a decrease in the threshold current for the operation of the power supply module 60.

Referring to FIGS. 14 and 15, the right side upper jaw holder 102 and the left side upper jaw holder 103 support the two upper jaws 6 and the jaw inserts 8. The long vertical through bolts 96 and 97 which are screwed into the threaded inserts 100 and 101 at the top and on the inside of the upper housing 2 fit through top holes 117 and 118 on the back and front of the right side upper jaw holder 102 on the right side. Also, flush mount screws 119 and 120 are inserted on the back and through corresponding holes in the right side upper jaw holder 102 and are screwed into the upper housing. The flush mount screws 119 and 120 are installed before the upper jaws 6 and inserts 8 are mounted to the right side upper jaw holder 102. The same arrangement for mounting the left side upper jaw holder 103 is followed using screws 121 and 122.

Right and left upper jaw keepers 123 and 124 prevent the upper jaws 6 from dropping down on the inside, because spring pins 126 and 127 are located on the outside and when depressed snap into the holes 128 and 129 of the right side upper jaw holder 102. The same procedure is followed with the left upper jaw keeper 124.

The jaw inserts 8 on the right and left sides of the STR unit 1 and in front of the upper jaws 6 are held in place by inserting threaded bolts 130 and 131 into each insert 8 and through the right and left keepers 123 and 124 and screwing into the upper jaw holders 102 and 103. The spring pins 132 and 133 are included in the lower jaw 7 which when depressed snap into the two holes 15 in the lower jaw holder 16.

The transmitting and receiving antenna 81 for the on-board transmitter and receiver 64 shown in FIG. 9 is mounted on the housing 2. The antenna 81 is displayed in FIGS. 1 and 2 and is installed on the top left side in FIG. 1. A solar sensor assembly 134 is located at the top of this housing and on its vertical centerline (FIG. 13). The small hole 140 located directly to the right of the conductor 1 allows access and adjustment of the electric power line sag sensor (FIG. 1).

The solar sensor assembly 134, similar to a pyranometer, is located on the top of the housing 2 and on the vertical centerline of the conductor C as shown in FIGS. 3 and 4. In FIGS. 3 and 4, the top surface of the solar sensor assembly 134 is level with the top of the transmitting and receiving antenna 81, so that the transmitting and receiving antenna 81 does not cast a shadow over the surface of the solar sensor assembly 134.

The solar sensor assembly 134 includes a solar radiation sensing element 282 having twisted and electrostatically shielded lead wires 284 and 285, as shown in FIG. 17. The solar sensor assembly 134 including the lead wires 284 and 285 can be easily removed from the top of the STR unit 1 by simply unscrewing an electrically conductive bezel 281 shown in FIG. 17.

The solar radiation sensing element 282 of FIGS. 17 and 18 is a commercially available 5 mm×5 mm silicon photovoltaic gridded solar cell having a 6.1 milli-ampere maximum output current when 100 watts per square foot of solar radiation is normal to the horizontal surface of this cell. The solar radiation sensing element 282 is placed in the center of a cell holder 283 and includes a non-reflective white high temperature plastic thin wafer with lead wires 284 and 285. The lead wires 284 and 285 output a dc voltage of 0.4 volts at 100 watts per square foot of solar radiation and after having been processed through the signal conditioning circuit of the sensor electronics module 63 produce a dc output voltage of 4.0 volts.

The maximum operating temperature of the cell holder 283 is 204° C. The lead wires 284 and 285 extend through two semi-circular cutouts of the cell holder 283 and pass into a slot 286 of a lead spacer 287 which is formed from the same material as the cell holder 283. The lead spacer 287 supports the back of the solar radiation sensing element 282, while providing a space in the form of a slot for the lead wires 284 and 285 to occupy. The lead wires 284 and 285 are twisted to prevent electromagnetic interference created by the current in conductor C from affecting the output signal. The lead wires 284 and 285 extend through a small offset hole 288 in a lead grommet 289 which is also formed of the same material as the cell holder 283 and then passes through a central hole 290 in a filler 291.

The filler 291 allows access for an electrically conductive ground strap 292 to be bonded to the inside wall at point 294 just above the inside threads of the bezel 281 shown in FIG. 17. This allows the solar sensor assembly 134 of FIGS. 17 and 18 to be unscrewed from an electrically conductive mount ring 295 shown in FIGS. 19, 20 and 21.

A glass circular beveled edge lens 296 shown in FIGS. 17 and 18 includes a transparent electrically conductive substrate 297 on the bottom made of indium—tin oxide which provides a combination of low resistivity (less than 40 ohms/square) and high transmittivity of 94% within the sunlight's wavelength range of 0.230 milli-microns to 3.000 milli-microns (230 nm to 3000 nm). The transparent electrically conductive coating 297 creates a Faraday cage over the solar radiation sensing element 282 and thus isolates the solar radiation sensing element 282 from the high electric field surrounding the high voltage conductor C.

Since the STR unit 1 and the housings 2 and 3 are at the same voltage as the conductor C, the bezel 281, which is screwed onto the mount ring 295, and a solar mount 298, which is attached to housing 2, are all at the same voltage potential as the conductor C. (See FIG. 13). The electrostatic shielding function of the conductive coating 297 prevents the solar radiation sensing element 282 from being exposed to the high electric field and thus the solar radiation sensing element 282 does not create a corona discharge which would destroy the solar radiation sensing element 282.

To connect the conductive coating 297 to the bezel 281, the ground strap 292 is bonded to the conductive coating 297 at point 293 and to the bezel 281 at the point 294 using an electrically conductive epoxy as shown in FIG. 17. The space created by the ground strap 292 and between the conductive coating 297 on the bottom of the glass circular beveled edge lens 296 and the solar radiation sensing element 282 is filled with a clear, colorless, easily pourable, silicone rubber dielectric compound 299 which has a useful operating temperature range from −60° C. to 204° C.

The solar sensor assembly 134 is installed on the STR unit 1 by inserting the solar mount 298 from the inside of housing 2 without the mount ring 295 and bezel 281 into a top hole 300 of FIGS. 13 and 19. The solar mount 298 is secured with two screws 301 and 302. With the solar mount 298 in place, an “O” ring 303 is slid over the top of the threaded portion on top of the solar mount 298 as shown in FIGS. 19 and 20.

An electrically conductive flat washer 304 is then placed over the “O” ring 303, and the “O” ring 303 centers the flat washer 304 such that when the mount ring 295 is screwed down the mount ring 295 mates with the full top surface of the flat washer 304 and electrically grounds the mount ring 295 to the solar mount 298. This insures that when the bezel 281 containing the solar radiation sensing element 282 is screwed on, there is an electrical continuity path from the conductive coating 297, the ground strap 292, the bezel 281, the mount ring 295, the flat washer 304, and the solar mount 298 to the housing 2. The mount ring 295 contains two small vertical holes 305 and 306, as shown in FIG. 20, to accept a spanner wrench of which when inserted into the two holes 305 and 306 can easily tighten or remove 295 from the solar mount 298.

As shown in FIGS. 18 and 19, a Faraday cage completely surrounds the solar radiation sensing element 282. The Faraday cage includes the electrically conductive coating 297 spaced apart and on top of the solar radiation sensing element 282, the electrically conductive bezel 281 surrounding the sides of the solar radiation sensing element 282, the electrically conductive mount ring 295, the electrically conductive mount 298, the flat washer 304, and the housing 2 complete the bottom of the cage around the solar radiation sensing element 282. With a completely enclosed Faraday cage which is subjected to high power line voltages on its surface there is no electric field inside the cage and thus the sensing element cannot produce a corona discharge.

Once the solar sensor assembly 134 is mounted as shown in FIGS. 17 and 19, the electrostatically shielded and twisted lead wires 284 and 285 are fed to the sensor electronics module 63 of FIGS. 9 and 13, which in turn is powered by the power supply electronics module 60 of FIG. 9. The measurement error of the solar radiation sensor is approximately 3 percent after the sun's solar altitude reaches 13.75 degrees from the horizon at sunrise and sunset as shown in FIG. 17.

The total solar radiation on a horizontal surface values are sent to the transmitter-receiver unit 64 of the STR unit 1 shown in FIG. 9 where the data is then sent to remote location receivers on a real time basis. The received data is processed by offsite software which displays the data and calculates the real power output (kilowatts) of any solar panels (farms) that may be interconnected to the electric power line circuit upon which the STR unit 1 is located. This information may be used to control the output of solar panels and regulate the voltage on the circuit, since a kW injection of real power from the solar panels will cause the voltage to rise on the circuit.

The STR unit 1 measures solar radiation while attached to a power line conductor C. The sensor electronics module 63 signal conditions measured values of solar radiation and sends the signal conditioned measured values to a remote location with the transmitter-receiver unit 64 via the antenna 81 located within the STR unit 1 to a remote location on a real time basis. The signal conditioned measured values can be used to determine a current carrying capacity of the conductor C.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims. 

What is claimed is:
 1. A device for attaching to an electric power line conductor comprising: a housing including an opening for accepting the power line conductor and configured to be grounded to the power line conductor; at least one magnetic core configured to surround the power line conductor and power a power supply electronics module; and a solar sensing element configured to be mounted horizontally on the housing.
 2. The device of claim 1 wherein the solar sensing element is mounted under and adjacent a transparent lens that is undercoated with a transparent electrically conductive substrate, the transparent lens being mounted to an electrically conductive mounting structure which forms a Faraday cage completely surrounding the solar sensing element.
 3. The device of claim 2 wherein the solar sensing element includes a silicon photovoltaic solar cell mounted adjacent and under the transparent lens and a transparent dielectric located between the silicon photovoltaic solar cell and the transparent lens which isolates the top of the silicon photovoltaic solar cell from the transparent electrically conductive substrate.
 4. The device of claim 2 wherein the transparent lens is undercoated with an indium-tin oxide substrate.
 5. The device of claim 2 wherein the transparent lens is electrically grounded to an electrically conductive mounting structure which completely surrounds the solar sensing element.
 6. The device of claim 5 where the electrically conductive mounting structure includes an electrically conductive bezel for mounting the transparent lens therein, the electrically conductive bezel is grounded to the transparent electrically conductive substrate and the housing.
 7. The device of claim 3 including the photovoltaic solar cell configured to produce a voltage output proportional to an incident solar radiation when the sun's solar altitude measured from the horizon is greater than 13.75 degrees at sunrise and when the solar altitude is greater than 13.75 degrees at sunset.
 8. The device of claim 3, wherein the transparent lens, the transparent electrically conductive substrate, the transparent dielectric, the silicon photovoltaic solar cell, and output leads are contained within an electrically conductive bezel which is attachable to an electrically conductive mounting structure and grounded to the housing.
 9. The device of claim 8 wherein the silicon photovoltaic solar cell is mounted within an opening in a wafer that accepts the output leads.
 10. The device of claim 9 wherein the wafer is a non-reflective white thin high operating temperature tolerant plastic.
 11. The device of claim 8 wherein the bezel includes inside threads configured to screw onto outside threads of an electrically conductive mount ring, the mount ring contains a pair of diametrically opposed holes for screwing internal threads on the mount ring onto outer threads on an electrically conductive solar mount which is grounded to said housing.
 12. The device of claim 11 including an “O” ring placed over the external threads of the said solar mount which centers an electrically conductive flat washer upon the electrically conductive solar mount and an upper surface of the flat washer engages the bottom of the mount ring and a lower surface of the flat washer engages the top of the solar mount for providing a direct electrically conductivity path from the bezel to the mount ring to said solar mount and to the housing.
 13. A method of measuring solar radiation with a device configured to be attached to a power line conductor comprising: signal conditioning measured values of solar radiation; sending the signal conditioned measured values to a remote location with a transmitter-receiver unit located within a housing; powering a sensor electronics module and the transmitter-receiver unit from current flowing in the power line conductor; and processing the measured values to determine a current carrying capacity of the power line conductor.
 14. The method of claim 13 wherein the signal conditioned measured values are transmitted by the transmitter-receiver unit to a remote location receiver.
 15. The method of claim 14 wherein the measured values are transmitted by the said transmitter-receiver unit to the remote location receiver on a real time basis.
 16. The method of claim 14 wherein the measured values represent a real power output of solar panels inter-connected with the power line conductor for controlling the output of the solar panels and regulating a voltage of the power line conductor. 